1. Field of the Invention
The invention relates to a valve having a housing, a solenoid arranged in the housing, a pin movable by the solenoid and a piston connected to the pin.
2. Related Art
Such valves are used, among other things, as recirculation air valves in turbochargers in motor vehicles in order during thrust operation to release a bypass to the suction side and are consequently known. In order to prevent excessive braking of the turbocharger but also to ensure rapid start up, a rapid opening and closing of the valve is a significant requirement. In particular during closing, the immediate closure by the placement of the piston on a valve seat is a significant aspect. The valve seat is formed by the housing of the turbocharger to which the valve is flanged. This results in the valve seat not being completely parallel with the piston, which would be required for a rapid and above all sealed closure action. In order nonetheless to ensure reliable closure, the piston has to adapt to the valve seat. To this end, it is known to construct the piston as an annular base member having fingers that protrude radially inwards in an oblique manner and engage in a radially peripheral groove of the pin. As a result of their resilience, the fingers enable a movement of the piston relative to the pin. It has been found that, as a result of production and assembly tolerances, the piston and pin are not connected to each other in a play-free manner, which results in disadvantages when closing the valve.